Process for producing enriched artificial rice

ABSTRACT

An enriched artificial rice having grains of good mechanical strength and resistant to washing, soaking, and cooking without losing their similarity to natural rice grains is prepared by heating a mixture of amino acids, starch and enough water to make the water content of the mixture 20 percent to 50 percent at 90* to 120* C. for 45 minutes to 1 minute, whereby the starch is semigelatinized. Starch or gluten is thereafter added as a binder to produce a second mixture which is granulated to the shape of rice grains, and the artificial grains are dried and coated with a waterproofing material.

United States Patent Inventors Appl. No. Filed Patented AssigneePriority PROCESS FOR PRODUCING ENRICHED ARTIFICIAL RICE 8 Claims, NoDrawlngs US. Cl 99/80 R, 99/83 Int.Cl A23l l/I0 Field of Search 99/80 R,

[56] References Clted UNITED STATES PATENTS 3,23l,388 l/l966 White 99/80PS OTHER REFERENCES Bhatia et al., Food Manufacture Sept. I956, pages376- 380- article entitled Substitute Foods Kimura-Chemical AbstractsVol. 52 l7560, article entitled Artificial Rice Primary Examiner-RaymondN. Jones AnorneyKurt Kelman ABSTRACT: An enriched artificial rice havinggrains of good mechanical strength and resistant to washing, soaking,and cooking without losing their similarity to natural rice grains isprepared by heating a mixture of amino acids, starch and enough water tomake the water content of the mixture 20 percent to 50 percent at to C.for 45 minutes to 1 minute, whereby the starch is semigelatinized.Starch or glu ten is thereafter added as a binder to produce a secondmixture which is granulated to the shape of rice grains, and theartificial grains are dried and coated with a waterproofing material.

PROCESS FOR PRODUCING ENRICHED ARTIFICIAL RICE This invention relates toa method of producing artificial rice enriched with a large amount ofamino acids.

The enriched artificial ricelike grains by the known methods aresatisfactory only if breaking of grains during boiling is acceptable.

The present invention aims at the preparation of a granular, ricelikefood, hereinafter referred to as artificial rice, which is highlyenriched as could not be accomplished before, maintaining mechanicalstrength of the grains and preventing dissolution of enriching nutrientsfrom the grains into water during washing and soaking.

Amino acids cannot be formed into grains when mixed with water. Whenthey amount to 6-50 percent by weight in the grains formed by mixingamino acids with starch or protein, the obtained grain is rather brittleand its hardness is merely 1-2 kg. by hardness meter.

It has now been found that it is essential to mix the raw materials intwo steps.

The first step is to mix amino acids with starch, knead the mixture withwater and heat with steam; and the second step is to mix suitable bindersuch as gluten and starch (with vitamins and minerals, if necessary)with the product obtained in the first step and knead it with water. Theproduct of the second step is shaped in a granulator.

In the first step of mixing amino acids with starch, kneading themixture with water and heating it with steam, the crystals of the aminoacids employed are covered and solidified by starch, which makes themixing in the second step satisfactory and brings about good hardnessand elasticity and prevents breaking of the artificial rice grains.

Amino acids used in the first step are L-lysine hydrochloride,L-threonine, L- or DL-methionine and L- or DL-tryptophan. The starchemployed in the present method, should be waterproof and have a lowexpansion rate such as is found in cross-linked starch (for example,distarch phosphate, and starch cross-linked with epichlorohydrin andamylose (for example, corn amylose).

The ratio of amino acids and starch may be varied according to thedesired enrichment. The amount of water used for kneading the aminoacids and starch should be 20 to 50 percent based on the weight ofstarch, which is enough to gelatinize the starch partly during heatingwith steam.

The heat treatment is performed for partly gelatinizing the starch at90-l20 C. for 45 minutes to 1 minute. If the heat treatment is moresevere, the starch granules are expanded and broken. The viscosity andelasticity of the starch and its ability to form grains are reduced asits tackiness increases, so that uniform grains of artificial rice cannot be obtained. If the heat treatment with steam is performed at lowertemperature for a shorter time, the starch granules do not gelatinizeand do not adhere to nutrients.

The term partly gelatinized starch or semigelatinized starch" refers toan intermediate phase between the above two states, in which starchkeeps its granule form and is strongly tacky at the same time.

In the second step, gluten and/or starch, and optional vitamins andminerals are added. Glutens are especially effective for maintaining themechanical strength of the grains during boiling. Water is added asneeded and the mixture is kneaded. The water content of the mixture atthe time of forming grains is preferably 28 to 40 percent.

Wheat gluten, corn gluten, and purified soybean protein are mostsuitable, and preferably amount to about -50 percent of the product.After mixing in the second step, the mixture is formed into grains anddried.

The grains formed are dried in warm air of less than 80 C. for asuitable time, until the water content is reduced to about 5-l 5percent.

lt is necessary to coat the surface of the grains in order to avoidleaching of the nutrients during prolonged washing and soaking.

It is known to gelatinize the surface of rice with formaldehyde and tocoat the surface of rice with vinyl resin. it has been found that acoating of shellac or ethylcellulose greatly improves the waterresistance of the artificial rice.

When cross-linked starch or amylose is sued in the first step,dissolution of amino acids during washing and soaking can be avoidedadequately even if a pinhole happens to be in the coating.

The artificial rice produced according to the method of the presentinvention has adequate hardness and elasticity and a high content ofnutrients. lt resists washing and soaking for a long time. Accordingly,this artificial rice can be mixed with natural rice prior to cooking asusual. When cooking is finished, its grains are not broken and there isno difference between the artificial rice and the natural one inviscosity, elasticity and taste.

EXAMPLE I To a mixture of 400 g. of distarch phosphate, 140 g. of L-lysine hydrochloride and 70 g. of L-threonine, 300 ml. of water wasadded and the mixture was heated at l00 C. for 35 minutes with steam,whereby starch granules were semigelatinized. Then g. of corn starch,200 g. of wheat gluten, 20 g. of calcium carbonate and 150 ml. of waterwere added, and the mixtures so obtained was rolled into sheets (watercontent 33 percent) which were converted to grains in a double rollergranulator.

The grains were screened and only rice-shaped grains were put into adryer to reduce their water content to 13 percent. An alcohol solutioncontaining 34 percent of shellac was sprinkled (30 ml. at one time) onthe grains in a pancoating machine under warm air of 4060 C. until theadded amount of shellac reached 80 g. The artificial rice thus producedwas white, contained L-lysine hydrochloride ll percent, L- threonine 5.5percent and water 4 percent, had a hardness of 10 kg. by hardness meter,and could hardly be distinguished from natural rice in appearance andtaste.

For comparison purposes, 490 g. of corn starch, 140 g. of L- lysinehydrochloride, 70 g. of L-threonine, 200 g. of wheat gluten, 20 g. ofcalcium chloride and 300 ml. of water were mixed and put into agranulator. The grains obtained were heated with steam at C. for 3minutes. The grains were not uniform and adhered to one another so thattheir surface became rough when they were separated. Although the grainswere coated according to the method mentioned above, they broke and losttheir shape during cooking after soaking in water.

EXAMPLE 2 To 460 g. of amilose of corn starch, g. of L-lysinehydrochloride and 70 g. of L-threonine, ml. of water was added and mixedwell. The mixture was heated with steam at 120 C. for 10 minutes, and130 g. of corn gluten, 100 g. of corn starch, 20 g. of calciumcarbonate, 0.6 g. of vitamin A, O.l g. of vitamin B, hydrochloride and200 g. of water were mixed in thereafter. The product 1,000 g. wasfinished by the same methods as in example 1.

.EXAMPLE 3 To the mixture of 227 g. of epichlorohydrin cross-linkedstarch, 333 g. of L-lysine hydrochloride, 83.5 g. of L- threonine and83.5 g. of DL-methionine, of water was added and mixed well. The starchwas semigelatinized by heat treatment with steam at 100 C. for 35minutes, and then 54 g. of wheat gluten, 0.4 g. of vitamin Bnaphthalenedisulfonate, 0.1 g. of vitamin B 20 g. of calcium carbonateand 8 g. of ferrics phosphate. Four hydrates were added and mixed well.The obtained mixture was put into a macaroni form granulator and formedto rice-shaped grains whose water content was reduced to 15 percent bydrying with warm air at 70 C. The dried grains were coated by sprayingwith an alcohol solution containing 10 percent of shellac and 1 percentof ethylcellulose on an automatic coating machine under Warm aeration at40 C.

What we claim is:

l. A method of producing artificial rice essentially consisting ofstarch, amino acid, and a binder which comprises:

a. mixing said amino acid with starch and with enough water to malke thewater content of the resulting initial mixture 20 percent to 50 percent;

b. heating said mixture with steam until said starch is semigelatinized;

c. thereafter adding to said mixture a binder selected from the groupconsisting of starch and gluten to produce a binder-bearing mixture;

d. shaping grains resembling rice grains from said binderbearingmixture;

e. drying said grains to a water content of substantially more than 15percent; and

f. coating the dried grains with water-proofing material.

2. A method as set forth in claim 1, wherein said initial mixture isheated at 90 to 120 C. for 45 minutes to 1 minute.

3. A method as set forth in claim I, wherein said amino acid is selectedfrom the group consisting of L-lysine, L-threonine, L- andDL-methionine, and L- and DL-tryptophan.

4. A method as set forth in claim 1, wherein the water content of saidbinder-bearing mixture is adjusted to 28 percent to 40 percent prior tosaid drying.

5. A method as set forth in claim 1, wherein said grains are dried at atemperature below C. to a water content of 5 percent to 15 percent.

6. A method as set forth in claim 1, wherein said water proofingmaterial is shellac or ethylcellulose.

7. A method as set forth in claim 1, wherein said initial mixture isheated at to C. for 45 minutes to 1 minute, the water content of saidbinder-bearing mixture is adjusted to 28 percent to 40 percent prior tosaid drying, and said grains are dried at a temperature below 80 C.

8. A method as set forth in claim 7, wherein said amino acid is selectedfrom the group consisting of L-lysine, L-threoninc, L- andDL-methionine, and L- and DL-tryptophan, and amounts to 6 percent to 50percent of the weight of said food.

* t t t i

2. A method as set forth in claim 1, wherein said initial mixture isheated at 90* to 120* C. for 45 minutes to 1 minute.
 3. A method as setforth in claim 1, wherein said amino acid is selected from the groupconsisting of L-lysine, L-threonine, L-and DL-methionine, and L- andDL-tryptophan.
 4. A method as set forth in claim 1, wherein the watercontent of said binder-bearing mixture is adjusted to 28 percent to 40percent prior to said drying.
 5. A method as set forth in claim 1,wherein said grains are dried at a temperature below 80* C. to a watercontent of 5 percent to 15 percent.
 6. A method as set forth in claim 1,wherein said water proofing material is shellac or ethylcellulose.
 7. Amethod as set forth in claim 1, wherein said initial mixture is heatedat 90* to 120* C. for 45 minutes to 1 minute, the water content of saidbinder-bearing mixture is adjusted to 28 percent to 40 percent prior tosaid drying, and said grains are dried at a temperature below 80* C. 8.A method as set forth in claim 7, wherein said amino acid is selectedfrom the group consisting of L-lysine, L-threonine, L-and DL-methionine,and L- and DL-tryptophan, and amounts to 6 percent to 50 percent of theweight of said food.